CVE-2026-64172
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Disable AVIC IPI virtualization on Hygon Family 18h (erratum #1235) Hygon Family 18h CPUs are derived from AMD Family 17h (Zen1) silicon and share the same erratum #1235: hardware may read a stale IsRunning=1 bit during ICR write emulation and silently fail to generate an AVIC_IPI_FAILURE_TARGET_NOT_RUNNING VM-Exit on the sending vCPU. The absence of the VM-Exit causes KVM to miss the required wakeup of blocking target vCPUs, leading to hung vCPUs and unbounded delays in guest execution. Extend the existing AMD Family 17h erratum #1235 workaround to also cover Hygon Family 18h. With IPI virtualization disabled, KVM never sets IsRunning=1 in the Physical ID table, so every non-self IPI generates a VM-Exit and is correctly emulated.
Affected versions
Linux kernel versions
6.17
and later are affected. Fixed in
6.18.34,
7.0.11,
7.1
and their respective stable series.
References
3 totalFrequently asked questions
-
What is CVE-2026-64172?
CVE-2026-64172 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.17 onward and has been patched in 6.18.34, 7.0.11 and 7.1. CVE-2026-64172 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
Is there a patch available for CVE-2026-64172?
Yes — CVE-2026-64172 has been patched. Fixed versions include 6.18.34, 7.0.11 and 7.1. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-64172 actively exploited?
No — CVE-2026-64172 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.